Table 1.

Baseline characteristics of the 17 107 adults aged ≥65 years with unknown atrial fibrillation status

Variable	15 intervention practices	16 control practices
Patient characteristics
Number of patients, n	8581	8526
Mean age, years (SD)	74.3 (7.3)	74.5 (7.3)
Females, n (%)	4680 (54.5)	4610 (54.1)

Medical history as collected in a random sample of 10% of both intervention and control group^a
Sample size of random samples, n	867	848

Comorbidities, n (%)
Hypertension	441 (50.9)	427 (50.4)
Type 2 diabetes	172 (19.8)	145 (17.1)
COPD	70 (8.1)	68 (8.0)
Prior myocardial infarction	59 (6.8)	57 (6.7)
Ischaemic stroke^b	34 (3.9)	54 (6.4)
TIA	40 (4.6)	40 (4.7)

↵a Because of rounding at practice level, sample size is not an exact 10% in either the intervention or control arm.
↵b Strokes were defined as either ischaemic or stroke of undefined origin. COPD = chronic obstructive pulmonary disease. SD = standard deviation. TIA = transient ischaemic attack.